Hi Justin, I just bought a stand-up stringer (an old Prince Ektelon) second-hand, and am starting to learn how to string. However, I’ve noticed that after finishing racquets, the strings are already slightly notched. (Last week, this happened to a set of Head Intellistring.) This occurs before I’ve even gone out to hit with the racquet. How do I prevent this from happening?—Joe B.

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What you’re describing sounds like friction burn—i.e., notching that occurs when cross strings are threaded and pulled across the mains too rapidly and/or not with enough arc. Friction burn can do a fair amount of damage to strings, especially those manufactured with little to no outer coating, like fine multifilaments and uncoated natural gut. As such, it’s important to pull crosses correctly.

Here’s how: Don’t pull the string at a beeline from grommet to grommet. Instead, follow the U.S. Racquet Stringers Association’s recommendations, as laid out in their Racquet Service Techniques Manual: “[U]se your fingers to slide the cross string at a diagonal angle,” while pulling at a moderate pace. By varying the contact points between cross and mains, you’ll reduce friction build-up and prevent premature string wear.